I don't think that's true at all. Last I checked, the crossover point was 6+ targets for Retribution. For us it's even lower thanks to a severely nerfed Censure. Probably 3+ targets for us, I'd guess (aoe sims should be forthcoming within a week or two, they're written, I just need some time to sit down and work out a comprehensive list of queues).

That said, I don't think there'd be much harm in buffing SoR for either/both spec (in our case, they'd have to buff SoT slightly too to keep it ahead of SoR on single targets). On the other hand, you have to waste a GCD to swap seals, whereas you don't need to change anything to switch to HotR/DivStorm. It's probably more convenient to not have to change seals except for very large groups.